Business Rules and Data Modeling Concepts

What is a business rule in the context of data modeling?

• A statement defining organizational goals. 

•  A rule that specifies how data should be processed.

• A statement that defines or constrains some aspect of a business. 

• A guideline for writing SQL queries.

Which of the following is NOT a characteristic of a good business rule?

• Precise

• Ambiguous

• Atomic

• Business-Oriented

An entity in an E-R diagram represents:

• A single instance of data.

• A property or characteristic of a data object.

• A collection of related data items.

• A person, place, object, event, or concept.

What is the primary purpose of a unique identifier for an entity?

• To store multiple values for a single attribute.

• To establish a connection between two entities.

• To uniquely distinguish each instance of the entity.

• To act as a derived attribute

Which of the following best describes a composite attribute?

• An attribute that cannot be broken down into smaller components.

• An attribute that contains multiple values for each instance.

• An attribute composed of multiple meaningful subparts.

• An attribute calculated from other attribute values.

In a one-to-many relationship:

• Each instance of one entity can be associated with many instances of another entity.

• Each instance of one entity must be linked to only one instance of another entity.

• Many instances of both entities can be linked to each other.

• One instance of each entity can be linked to exactly one other instance.

Which of the following relationships would typically require an associative entity?

• Employee manages Department

• Student enrolls in Course

• Customer places Order

• Product has Description

Cardinality constraints specify:

• How many entities can participate in a relationship.

• The sequence in which data is processed.

• The structure of an associative entity.

• The storage requirements for a database.

Which of the following is a unary relationship?

• Employee supervises Employee

• Customer places Order

• Student enrolls in Course

• Vendor supplies Product

A weak entity:

• Can exist independently without any other entity.

• Has a unique identifier.

• Depends on a strong entity for its identification.

• Represents an abstract concept.